An injection sprayer is a sprayer in which the carrier liquid, which may be water or a solution, mixture or suspension of another material in water, is fed to the spray nozzles of the apparatus from one supply, while an additive, for example a pesticide, is injected from another source into the water passing through the supply lines. This avoids the need to premix the additive and the carrier.
Various injector systems of this type have been proposed in the past. The known systems suffer from certain disadvantages, including the inability of the additive metering system to handle materials with widely varying viscosities, at widely varying temperatures and at different dilution rates.
The present invention is concerned with an improved apparatus of this type.